Water Boiling at Everest - Periodic Table of Videos

I love that these two (probably more, we see another guy filming things at one point) guys boiled water at all these elevations to see what the temperature of the boiling water would be.

Whenever in class we talk about the boiling point of water dropping in temperature as the outside air pressure dropped, I make up a number and say that water on top of Mount Everest boils at that temperature. In fact, I've never looked up the exact theoretical temperature. As far as I know, though, nobody has ever been to the top of Mount Everest and taken the time to do the actual experiment. That's mostly, though, because by the time you get to Mount Everest's peak, you're pretty much on your way to dying and every thought has to be focused on just trying to survive.

For explanation on why the boiling point of a liquid drops as the external pressure on the liquid drops, check out the follow-up video.

Seeing the Invisible

This video starts nearly silently, and that's understandable as it's some amazing video.

Schlieren photography is apparently phenomenal, because it lets us see very slight differences in densities of gases.

Seriously, I could watch this video again and again.

I'll put some more Schlieren videos after the jump...

Mock Apple Pie

I've made and served Mock Apple Pie before, though mine didn't have the crumble topping like that shown up above. That's a nice touch and would likely make the whole thing a little more believable.

Admittedly, the texture is that of over-cooked apples rather than the ideally still-crisp apples in the best pies, but it's generally a decent 'apple' pie to serve. Proves that much of what we taste is based on a lot more than purely what we're really tasting. If the smell and consistency and look are all about right, we'll go for it.

Learn more about Mock Apple Pie on C&EN's website or by searching for a recipe.

6 Chemical Reactions That Changed History

So much stuff to say here...

• 6 - Maillard Reaction(s) - There are actually a whole bunch of reactions that fall under the umbrella of Maillard Reaction(s) so, the name should really be plural...There's also some idea that the Maillard Reactions produce some carcinogenic by products. 
• 5 - Bronze - By all the definitions I've ever heard, alloying metals doesn't qualify as a chemical reaction. It's an important process, yes, but not necessarily a chemical reaction...Did he really say, "pokey sticks"?...sheesh...
• 4 - Fermentation - Again, lots of different chemical reactions coming under one big umbrella there...and there's no mention of the actual chemical reaction that takes place within the yeast and other microorganisms that actually do the fermenting.
• 3 - Saponification - This one gets the best explanation of the actual chemical reaction happening between the triglyceride and the base. Thanks...
• 2 - Silicon - Again, melting and recrystallizing anything isn't a chemical reaction...it's impressive and well worth studying, but it's misleadingly placed in this video.
• 1 - Haber-Bosch process - This one's massively important, agreed. Easily the best choice in the video. I'd put one other reaction above this one, but it's certainly not a modern one.

And the narrator's a little annoying...but that's sort of me being catty.